• MCU: ESP32-DEVKITC
• Framework: Arduino
• Build system: PlatformIO
• Board target: esp32dev
• Purpose: Leer joystick, 4 botones, batería, USB conectado y controlar LED rojo de batería baja.

• CHRG red LED and FULL green LED are hardware-controlled by TP4056 CHRG/STDBY pins, not by firmware.
• GPIO34 and GPIO35 are input-only, correct for ADC sensing.
• Joystick/button signals can be sent over WiFi/BLE later; this starter prints to Serial.

Ini
[env:esp32dev]
platform = espressif32
board = esp32dev
framework = arduino
monitor_speed = 115200
upload_speed = 921600

Cpp
#include <Arduino.h>

// Pin definitions from schematic
#define JOY_X_PIN              32
#define JOY_Y_PIN              33
#define BAT_SENSE_PIN          35
#define VBUS_SENSE_PIN         34
#define JOY_SW_PIN             25
#define BTN1_PIN               18
#define BTN2_PIN               19
#define BTN3_PIN               21
#define BTN4_PIN               22
#define LOW_BAT_LED_PIN        23

// ADC scaling
// Battery and VBUS dividers are 100k/100k, so input voltage = ADC node * 2.
#define ADC_MAX_COUNTS         4095.0f
#define ADC_REF_VOLTS          3.3f
#define DIVIDER_RATIO          2.0f

// Battery thresholds for 1S LiPo
#define BAT_LOW_VOLTS          3.50f
#define BAT_CRITICAL_VOLTS     3.30f

static unsigned long lastReportMs = 0;
static const uint32_t REPORT_INTERVAL_MS = 100;

float readAdcVoltage(int pin) {
  int raw = analogRead(pin);
  return (raw / ADC_MAX_COUNTS) * ADC_REF_VOLTS;
}

float readBatteryVoltage() {
  return readAdcVoltage(BAT_SENSE_PIN) * DIVIDER_RATIO;
}

float readVbusVoltage() {
  return readAdcVoltage(VBUS_SENSE_PIN) * DIVIDER_RATIO;
}

int readButtonActiveLow(int pin) {
  return digitalRead(pin) == LOW ? 1 : 0;
}

void setup() {
  Serial.begin(115200);
  delay(300);
  Serial.println("ESP32 robot-car remote control starting");

  analogReadResolution(12);
  analogSetAttenuation(ADC_11db); // allows readings up to about 3.3V on ADC pin

  pinMode(JOY_SW_PIN, INPUT_PULLUP);
  pinMode(BTN1_PIN, INPUT_PULLUP);
  pinMode(BTN2_PIN, INPUT_PULLUP);
  pinMode(BTN3_PIN, INPUT_PULLUP);
  pinMode(BTN4_PIN, INPUT_PULLUP);

  pinMode(LOW_BAT_LED_PIN, OUTPUT);
  digitalWrite(LOW_BAT_LED_PIN, LOW);
}

void loop() {
  unsigned long now = millis();
  if (now - lastReportMs < REPORT_INTERVAL_MS) {
    return;
  }
  lastReportMs = now;

  int joyX = analogRead(JOY_X_PIN);
  int joyY = analogRead(JOY_Y_PIN);
  float batteryV = readBatteryVoltage();
  float vbusV = readVbusVoltage();

  bool lowBattery = batteryV < BAT_LOW_VOLTS;
  bool criticalBattery = batteryV < BAT_CRITICAL_VOLTS;
  bool usbConnected = vbusV > 4.0f;

  digitalWrite(LOW_BAT_LED_PIN, lowBattery ? HIGH : LOW);

  int joySw = readButtonActiveLow(JOY_SW_PIN);
  int b1 = readButtonActiveLow(BTN1_PIN);
  int b2 = readButtonActiveLow(BTN2_PIN);
  int b3 = readButtonActiveLow(BTN3_PIN);
  int b4 = readButtonActiveLow(BTN4_PIN);

  Serial.printf(
    "JOY_X=%d JOY_Y=%d JSW=%d B1=%d B2=%d B3=%d B4=%d VBAT=%.2fV VBUS=%.2fV USB=%d LOW=%d CRIT=%d\n",
    joyX, joyY, joySw, b1, b2, b3, b4, batteryV, vbusV,
    usbConnected ? 1 : 0,
    lowBattery ? 1 : 0,
    criticalBattery ? 1 : 0
  );
}

Bash
pio run
pio run -t upload
pio device monitor